For shoppers looking for a last-minute present, Bellevue firefighters say carbon monoxide detectors make great gifts. To be required in rental units in Washington state starting Jan. 1, CO detectors alert residents when dangerous levels of the odorless gas are reached.

Carbon monoxide poisoning, most often occurring when someone tries to heat their home during a power outage by bringing a grill or gas generator inside, kills more than 500 people and accounts for an estimated 20,000 emergency department visits annually in the U.S.

Fire officials recommend installing a carbon monoxide detector on each floor of your home, near bedrooms especially. The Bellevue Fire Department sent notices to the management companies and landlords for the thousands of apartments in the city, informing them of the new state requirement for CO detectors. In existing residences, detectors can be plug-in, battery-operated or hard-wired.

There are two exceptions to the new law

Owner-occupied, single-family residences. However, to sell a home, the seller must equip the residence with carbon monoxide alarms before the buyer or any other person may legally occupy the residence.